I’ve been doing Jims work a lot in the past, let me chime in as well.
That turned out to be a long rant, sorry.
TL:DR: use the right TM, use 50% for BBB set for the whole cycle. Do 2 cycles of 5PRO and one cycle of PR sets.
Put all effort in the main lift, some in the supplemental and just get the assistance done.
Of the bat: as everyone have said, use the appropriate TM. That would be a 5RM where you’d be able to do at least one more grindy rep. NOT a true 5RM. You’ll get to heavy weights soon enough.
I think you’re doing BBB with FSL that is very very taxing. Bench is a lift that most have done the most and is most efficient at, meaning you won’t progress as fast and easy as on squat and DL.
I would start out by doing BBB with 50% for the first cycle, that would be the same weight for 3 weeks. If you think it’s too light, then lower the weight slow, take a slight pause at chest, reduce rest time. First week take 70 sec pause second 60 sec last week 45 sec.
Remember the main work is where you really really put in all the work. The 3 main lifts is supposed to be really tight setup, performed with a controlled decent a slight pause and explode viciously on the concentric phase that’s for the press, bench and squat. DL tight setup and a fast explosive pull, hold the bar for a second control the bar all the way to the ground repeat.
THEN it’s time for supplemental work ie BBB or whatever you’d do after the main lift, those are not supposed to be hard and you should be able to get all the reps.
THEN it’s assistance that is what it is, assistance. It should be easy if dips are to hard then do push ups. It’s easy work.
Jims work is awesome, do it the right way, do it for a year and I’ll guarantee that after a year you’d be able to bench BBB with 135 lbs. and possibly have a TM at 225.
The bad news is, it takes time, it’s boring as hell, you feel you go nowhere.
Even worse news is there’s no program that’ll make you big and strong in 5 weeks.
You could take a look at nuttys beginner program as suggested it is a really good program.
OH btw stop testing, every month. Make a plan test every 6 month or so.
If you follow Jims work you’ll be increasing you TM every cycle, that means that on the last week of the cycle you’ll be able to “test” at some point you won’t be able to hit 5 reps.
If you want to test more go for PR sets on the main lift every 3 cycles, 2 cycles 5PRO, 1 cycle PR set. use the PR set on the last week to see if you need to reset the TM.